1 . My friend asked me to attach a stamp to the ________(信封) and mail it. (根据汉语提示单词拼写)

2 . The sound of the doors opening was made simply by pulling a sheet of paper out of an e______.(根据首字母单词拼写)

3 . As soon as he finished the letter, he took out of the e________ at once.

4 . When the New Year comes, adult give kids “lucky money” in red _________ (信封) . （根据汉语提示单词拼写）

5 . She folded the letter and then put it into the ______(信封). （根据汉语提示单词拼写）